Urgent considerations
See Differentials for more details
Severe elevations in blood pressure are classified as either emergencies or urgencies.[43] In hypertensive emergencies there is severe hypertension (>180/120 mmHg) with evidence of new or worsening end organ damage.[2] This is an immediate threat to the cardiovascular system and the patient. In hypertensive urgencies, there is severe hypertension but the patient is otherwise stable with no evidence of acute or impending change in end organ damage or dysfunction.[2]
True hypertensive emergencies include hypertensive encephalopathy, hypertensive left ventricular failure, and acute aortic dissection. The management of these conditions includes immediate treatment in an intensive care setting with controlled gradual reduction in blood pressure. Initial laboratory tests should include a full blood profile and urine analysis to search for an underlying cause. Tests such as cardiac enzymes, thyroid function tests, urinary catecholamines, and vanillylmandelic acid may also be required. Elevations in urea and creatinine, raised sodium and phosphate levels, high or low potassium levels (particularly in hyperaldosteronism, as a result of renal potassium wasting), and acidosis are some of the common findings.
Imaging studies such as a chest x-ray and renal ultrasound scan can also help to rule out underlying aetiology. Computerised tomography of the head to assess for intracranial haemorrhage or infarction or space-occupying lesions may also be indicated. A 12-lead ECG is useful to assess for cardiac ischaemia or infarct, presence of left ventricular hypertrophy, and evidence of electrolyte disturbance or effects of drug overdose. If left untreated, these conditions are associated with a high mortality and morbidity. Fortunately, with the widespread use of antihypertensive agents, they are less commonly seen overall.[43][44][45]
Specific hypertensive emergencies
Hypertensive encephalopathy
This is a symptom complex of severe hypertension with headache, vomiting, visual disturbance, mental status changes, seizure, and papilloedema. Cardiac symptoms such as angina, myocardial infarction, and pulmonary oedema may occasionally be the main presenting symptoms.
Hypertensive left ventricular failure
Symptoms are those of decompensated cardiac failure with shortness of breath, pulmonary oedema, lethargy, paroxysmal nocturnal dyspnoea, and orthopnoea. A cough productive of frothy pink sputum may be reported. Left heart failure can lead to bi-ventricular failure, and there may be signs of peripheral oedema and hepatomegaly. An echocardiogram will usually be indicated, and imaging of the coronary arteries may be helpful as reversible cardiac ischaemia may improve symptoms and prognosis.
Acute aortic dissection
Typically presents with acute, severe chest pain with 'ripping' or 'tearing' characteristics. It may radiate to the back or jaw. Syncope, altered cognition, and anxiety are common neurological symptoms. An interarm blood pressure difference of >20 mmHg is suggestive but not diagnostic of an acute aortic dissection. Treatment will depend on the portion of the aorta that is affected and may include surgical repair, endovascular stenting, or medical therapy alone. All patients require close monitoring and intensive treatment of blood pressure and pulse, usually in a high-dependency or intensive care unit with appropriate specialist input.
Hypertensive urgencies
Malignant or accelerated hypertension
Malignant hypertension is associated with potentially irreversible hypertension-mediated organ damage that occurs over days or weeks, rather than minutes, and is therefore classified as an urgency. It is characterised by very high blood pressure in association with bilateral retinal changes, including exudates and haemorrhages, with or without papilloedema. The most common symptoms include headaches (often occipital), visual disturbances, chest pain, dyspnoea, and neurological deficits. Consequences include cerebral infarction or haemorrhage, transient blindness or paralyses, seizures, stupor, or coma. Malignant hypertension often has a renal cause, and proteinuria, microscopic haematuria, red blood cell, and hyaline casts in urine are typical. See Hypertensive Emergencies.
Asymptomatic high blood pressure
This is a common occurrence, where an asymptomatic patient (either known to have hypertension on treatment or previously not known to have hypertension), is found to have very high readings in the 'accelerated hypertension' range. If there are any signs of retinal involvement, they should be managed as per 'malignant hypertension' or 'accelerated hypertension' guidelines. However, if there is no hypertension-mediated organ involvement, they should be evaluated for the cause of the high blood pressure.
If a patient is already on antihypertensive medications, care should be taken to check compliance or worsening renal function. If the increase in blood pressure has occurred over time, it could simply reflect the need to up-titrate drug dosage, as the current dosage may not be sufficient. A history of illicit drug use should also be sought, as this can cause a sudden increase in blood pressure. Screening for a secondary cause is also important.
If the patient is drug-naive, then they should be managed as per any individual with newly diagnosed hypertension, with screening for secondary causes, end organ damage, and cardiovascular risk.
Pre-eclampsia
Pre-eclampsia is new-onset persistent hypertension, with either proteinuria or evidence of systemic involvement, that occurs in pregnant women after 20 weeks' gestation. Women with pre-eclampsia require specialist obstetric care. The details of diagnosis and management are beyond the scope of this topic. See Pre-eclampsia.
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